Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2016
Publication Date: 7/11/2016
Publication URL: http://handle.nal.usda.gov/10113/5922787
Citation: Long, D.S., Mccallum, J.D., Martin, C.T., Capalbo, S.M. 2016. Net returns from segregating dark northern spring wheat by protein concentration during harvest. Agronomy Journal. 108(4):1503-1513. doi:10.2134/agronj2015.0457.

Interpretive Summary: Growers of dark northern spring wheat operate under a quality payment system that rewards them to maximize the protein concentration of their grain. It is known that protein concentration of grain varies within farm fields yet conventional harvesting ignores this variability and bulks the grain together in one bin. Specialized equipment is commercially available for measuring and mapping the protein concentration of grain within fields. The objective of this study was to determine if producers could profit by using this equipment to segregate the grain into two bins of low and high quality on the combine during harvest. Grain protein and yield data were obtained from 21 wheat fields in northern Montana. An economic analysis was undertaken of the costs and revenues generated with and without grain segregation. Segregation consistently increased the dollar value of each bushel of wheat, but revenues based on 16-year average prices was not enough to offset the associated costs. However, segregation was profitable in years of wide price spreads and above average yields. These results indicate that grain segregation may be profitable under certain conditions. Further refinements are needed to reduce equipment costs and benefit the producer.

Technical Abstract: In-line, optical sensing has been developed for on-combine measurement and mapping of grain protein concentration (GPC). The objective of this study was to estimate changes in costs and net returns from using this technology for segregation of the dark northern spring (DNS) subclass of hard red wheat (Triticum aestivum L.) by GPC. Site-specific grain protein and yield data were obtained from 21 DNS wheat fields in northern Montana over 11-yr (1994-2004). Several hundred measurements of GPC were obtained within each field by means of whole grain spectroscopy. A spreadsheet calculator was built to predict the best economic point at which to segregate grain into two bins and define the protein level and quantity of each segregated volume of grain. Partial budget analysis was used to estimate net returns and determine if segregating wheat in two bins was more profitable than bulking wheat in one bin. Segregation consistently increased the value of each Mg of grain if average GPC of a field was below the upper limit of a price schedule and did not coincide with a price point. Added income, however, was insufficient to offset costs of segregation based on 16-yr (1994-2010) average market prices. Net returns from segregating DNS wheat were $0.82 to $22.99 ha-1 greater than bulking in years with large spread between prices and above average yields. These results suggest that grain segregation may be profitable under limited conditions. Further refinements to the technique are needed to reduce equipment costs and benefit the producer.